package com.zhongcw.java.network.socket.example.sun;

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.net.*;
import java.io.*;

public class KnockKnockProtocol {
	private static final int WAITING = 0;
	private static final int SENTKNOCKKNOCK = 1;
	private static final int SENTCLUE = 2;
	private static final int ANOTHER = 3;

	private static final int NUMJOKES = 5;

	private int state = WAITING;
	private int currentJoke = 0;

	private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who",
			"Who" };
	private String[] answers = { "Turnip the heat, it's cold in here!",
			"I didn't know you could yodel!", "Bless you!",
			"Is there an owl in here?", "Is there an echo in here?" };

	public String processInput(String theInput) {
		String theOutput = null;

		if (state == WAITING) {
			theOutput = "Knock! Knock!";
			state = SENTKNOCKKNOCK;
		} else if (state == SENTKNOCKKNOCK) {
			if (theInput.equalsIgnoreCase("Who's there?")) {
				theOutput = clues[currentJoke];
				state = SENTCLUE;
			} else {
				theOutput = "You're supposed to say \"Who's there?\"! "
						+ "Try again. Knock! Knock!";
			}
		} else if (state == SENTCLUE) {
			if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) {
				theOutput = answers[currentJoke] + " Want another? (y/n)";
				state = ANOTHER;
			} else {
				theOutput = "You're supposed to say \"" + clues[currentJoke]
						+ " who?\"" + "! Try again. Knock! Knock!";
				state = SENTKNOCKKNOCK;
			}
		} else if (state == ANOTHER) {
			if (theInput.equalsIgnoreCase("y")) {
				theOutput = "Knock! Knock!";
				if (currentJoke == (NUMJOKES - 1))
					currentJoke = 0;
				else
					currentJoke++;
				state = SENTKNOCKKNOCK;
			} else {
				theOutput = "Bye.";
				state = WAITING;
			}
		}
		return theOutput;
	}
}
